Open top refrigerated display case system



.1. F. MERCER, SR

REFRIGERATED DISPLAY CASE SYSTEM May 10, 1966 5 Sheets-Sheet 1 Filed Nov. 2'7, 1964 I N V E NTOR. M 57% J. F. MERCER, SR

REFRIGERATED DISPLAY CASE SYSTEM May 10,1966

3 Sheets-Sheet 2 Filed Nov. 27, 1964 INVENTOR.

May 10, 1966 J. F. MERCER, SR

I I I REFRIGERATED DISPLAY CASE SYSTEM 3 Sheets-Sheet :5

FiledNov. 27,

INVENTOR.

BY 17%: 571m h United States Patent 3,250,085 OPEN TOP REFRIGERATED DISPLAY CASE SYSTEM John F. Mercer, Sr., P.O. Box 1143, Globe, Ariz. Filed Nov. 27, 1964, Ser. No. 414,228 6 Claims. (Cl. 62-256) The present invention relates in general to refrigerated open top display case systems for food products and the like and more particularly to a display case system comprising an open top display case having no evaporator in the display case which is coupled with a separately housed evaporator unit to circulate refrigerated air through the display case.

An object of the present invention is the provision of a refrigerated display case system having an open top coil-less display case formed as one structural unit and an evaporator unit as a separately housed unit supplying the display case with refrigerated air.

Another object of the present invention is the provision of a coil-less open top refrigerated display case structure which can be produced in modular units having no cooling coils or evaporator coils, and thus requiring no facilities for condensate collection and drainage, the modular units being adapted to be assembled into elongated display cases of desired length and coupled through supply and return air ducts to a separate evaporator unit.

Other objects, advantages, and capabilities of the present invention will become apparent fromthe following detail description taken in conjunction with the accompanying drawing illustrating preferred embodiments of the invention.

' In the drawings:

FIGURE 1 is a perspective view of an evaporator unit used in the refrigerated display case system of the present invention, with parts of the evaporator unit housing broken away to reveal the interior thereof;

FIGURE 2 is a perspective view of an open top refrigerated display case of one form which may be used in the system of the present invention, with parts of the case broken away; and

FIGURE 3 is a perspective view of a shelf type open top refrigerated display case which may be used in the system of the present invention.

Referring to the drawings, wherein like reference characters designate corresponding parts throughout the several figures, and particularly to FIGURE 1, there is shown an examplary form of the separately constructed evaporator unit, comprising a housing having a top wall 1 and a vertical end wall 2, having an opening 3 therethrough, for passage of outside air into the evaporator unit housing. In the specific embodiment illustrated, the evaporator unit contains three'stages of evaporating or cooling coils, the evaporator coils 4 being disposed nearest the end wall 2. A tranverse partition or divider wall 5 having an air passage opening 6 therein separates the second stage evaporating or cooling coil 7 from the evaporator coil 4. Likewise, a partition or divider wall 8 having an air passage opening 9 therein separates the third stage evaporator or cooling coil 10 from the coil 7. Adjacent the coil 10 to the opposite side thereof from the partition'8 is a blower or air circulating means 11 journaled for rotation in suitable mounting means and coupled, for example by a belt and pulley drive, with a drive shaft 12 journaled in the end wall 221 of the evaporator unit housing opposite the wall 2 and driven by a suitable electric motor 13 supported externally of the evaporator unit housing. One of the side walls'of the evaporator unit housing is indicated by the reference character 21 and the bottom of floor of the evaporator unit housing is designated by the reference the entire length of the display case.

3,250,085 Patented May 10, I966 'ice character 22. The vertical side wall 21a of the housing opposite and paralleling the side wall 21 is provided with access openings in the lowerportion thereof adjacent the blower 11 and in the compartment defined between the evaporator coil 10 and end wall 2a providing an opening 14 which is divided by a vertical partition at its center to define a high pressure air duct 14H and a low pressure air duct 14L for communication with a separately constructed open top display case to supply dehumidified refrigerated air through the high pressure duct 14H to the open top display case and return air from the display case to the evaporator unit. The reference characters AA denote the portion of the evaporator housing which is to be connected to the open top refrigerated display case unit.

One form of coil-less open top display case which may be coupled to the evaporator housing is illustrated in FIGURE 2 and comprises vertical side walls 18 extending in spaced parallelism having a cap or trim 17 around the top thereof, the side walls 18 being of the conventional insulating construction. These vertical side walls 18, together with the bottom wall 24 and vertical end wall 25 at one end only of the display case define an upwardly opening space which is divided-by a horizontal thermally conductive panel 26 into an upper product zone and a lower enclosed air circulating zone. A vertical partition 16 extends entirely between the bottom wall 24 and the panel 26 substantially midway betwen the two side walls 18 to define the elongated high pressure or air supply duct 14H and the low pressure or air return duct 14L which extend provided with a plurality of orifices or openings 19 in the portion thereof forming one of the bounding walls of the high pressure or air supply duct 14H at selected points along the length thereof to admit dehumidified refrigerated air from the supply duct 14H into the product zone. At the end of the display case closed by the end wall 25 the divider partition 16 is provided with an opening, for example by terminating the divider partition 16 at a point spaced from the end wall 25, whch opening is controlled by an adjustable door or panel 15 to regulate the'differential' pressures between the ducts 14H and 14L.

In the operation of the display case illustrated in FIG- URE 2, assuming the same to be connected at the end thereof opposite the end Wall 25 to the evaporator unit housing of FIGURE 1 at the zone indicated by the plane AA, the blower 11 produces a partial vacuum in the return duct 14L drawing air therefrom into the compartment defined between the evaporator coils 10 and end wall 2a of the evaporator unit housing to cool and dehumidify the air by thermal exchange with the evaporator coil 10. Some outside air will also be drawn through the opening 3 in the end wall 2 of the evaporator unit housing and will be pre-cooled by being drawn through the evaporator coils 4 and'7 and further cooled by the evaporator coil 10, which additional air approximately equals in weight the amount of air passing upwardly through the openings 19 and into the product zone of the display case. The refrigerated and dehumidified air in the compartment between the coils 10 and wall 2a is then discharged by the blower 11 into the supply duct 14H and forced along the length of the display case. The

product in the product zone is cooled both by direct 7 around, and through the product. Air which passes from the duct 14H through the opening adjacent the end wall 25 regulated by the adjustable door 15 is drawn from the The panel 26 is air return duct 14L into the evaporator housing unit to be recooled and recycled through the air supply duct 14H.

Another embodiment operating on substantially the same principle as the embodiment of FIGURE 2 is illustrated in FIGURE 3, wherein the display case is of the high back shelved type. In this embodiment, the rear wall 18' of the display case extends to a considerably greater heighth than the front wall 18, and the single thermally conductive panel 26 of the FIGURE 2 form and divider partition 16 are displaced by a pair of thermally conductive panels 27 and 28. The panel 27 extends in a vertical plane from the bottom wall 24 to the top wall 29 of the case to define the high pressure air supply duct 14H between the panel 27 and the rear vertical wall 18, and panel 28 extends between the vertical panel 27 and the front wall 18 in upwardly spaced relation to the bottom wall 24- to define the air return duct 14L therebetween. Plural shelves 23 are supported on the vertical panel 27 by conventional means and project outwardly toward the plane of the front Wall 18 and the air supply openings 19 are provided in the vertical panel 27 below the lowermost shelf 23 and above each of the shelves 23 to admit some of the dehumidified refrigerated air from the air supply duct 14H to the zones occupied by the product on the shelves 23. The referigerated air which passes through the openings 19 being heavier than the surrounding ambient air, will circulate'downwardly over the shelves 23 and overflow at the cap 17. As in the FIG- URE 2 embodiment, an opening is provided adjacent a vertical end wall at one end of the display case of FIG- URE 3 and regulated by an adjustable door 15 for the same purposes as the door 15 in the FIGURE 2 embodiment. FIGURE 2 also illustrates how greater air handling capacity can be achieved in an open display case of the type illustrated in FIGURE 2 by extending the vertical side walls 18 and bottom wall 24 a suitable distance below the floor line 20, as for example, where the ex-.

tensive length of the display case requires greater volume for the ducts ME and 14L than could be provided above the floor line in display cases of normal wall height.

It will be apparent that the display cases of FIGURE 2 and FIGURE 3 forms may be made up of a plurality of identical modules connected end to end to provide the display case of desired length, one of the end-most modules being closed by the end wall 25 and the outer end of the other end-most module being connected at the plane AA to the evaporator housing unit.

While several modifications of the present invention have been particularly shown and described, it will be apparent that various modifications may be made within the spirit and scope of the invention, and it is desired, therefore, that only such limitations be placed on the invention as are imposed by the prior art and set forth in the appended claims.

I claim:

1. A refrigerated display case system comprising an evaporator unit including a housing having return air and supply air access openings therein, evaporator coil means in said housing, and driven air circulating means in said housing for circulating air from said return opening over said coil means to cool and dehumidify the air and convey the same to said supply opening; an open top display case having no coils therein forming a physically separate structure relative to said evaporator housing to be coupled to said evaporator unit to receive air from and return air to said evaporator unit, said display case having a bottom wall and side walls and an end wall remote from the evaporator housing collectively defining an upwardly opening space between said walls, thermally conductive panel means within said space disposed in substantially parallel relation to and spaced from at least one of said walls dividing said space into elongated air circulating duct means and an upwardly opening product zone disposed above at least a portion of said duct means each extending substantially the entire length of the display case, a divider partition in said duct means dividing the space in said air circulating duct means into a refrigerated air supply duct and an air return duct, said air supply duct being bounded on one side by at least a portion of said panel means along the length of the display case to coo-l product in said product zone by direct thermal transfer therefrom through said panel means portion to dehumidified refrigerated air in said air supply duct, orifice means at selected spaced points along said supply duct to admit air therefrom into said product zone, said divider partition having an opening adjacent the remote end wall of said display case to communicate air from said supply duct to said return duct, and means communicating said supply duct and said return duct respectively with said supply and return access openings at the opposite end thereof relative to said remote end wall.

2. A refrigerated display case system as defined in claim 1, wherein said panel means is formed of a bottom panel spaced above and substantially paralleling said bottom wall which completely spans the distance between said side walls to define said air circulating duct means wholly below said bottom panel between the latter and said bottom wall, said divider partition being a vertical partition extending in a vertical plane from said bottom panel to said bottom wall parallel to the longitudinal axis of said display case to locate said air supply duct and air return duct in side-by-side relation extending the length of the case.

3. A refrigerated display case system as defined in claim 2, wherein said case includes an adjustable door for said opening in said divider partition to vary the differential pressure between said air supply duct and said air return duct.

4. A refrigerated display case system as defined in claim 1, wherein one of said side walls of said display case is of greater height than the other side wall, said panel means including a vertical side panel spaced from 'and substantially paralleling the taller side wall and extending to said bottom wall todefine said air supply duct between said vertical panel and said taller side wall along the height thereof and also form said divider partition, a plurality of shelves supported on said vertical panel and extending therefrom into the product zone, and said panel means also including a bottom panel spaced above and substantially paralleling said bottom wall extending between said vertical panel and the shorter of said side walls to define said air return duct between said bottom panel and said bottom wall.

5. A refrigerated display case system as defined in claim 1, wherein said evaporator unit housing forms an end wall for the end of said display case opposite said remote end wall, said evaporator unit comprising a plurality of evaporator coil stages, said housing having a first compartment in a portion of said housing in direct communication with said return air and supply air access openings, one of said evaporator coil stages extending into said first compartment in exposed relation to air therein to cool the air, and said air circulating means comprising a blower located in said first compartment to draw air through said return air access opening into said first compartment, circulate the same in said first compartment in thermal exchange relation with said one evaporator coil stage, and force the air outwardly through said supply air access opening to said air supply duct.

6. A refrigerated display case system as defined in claim 5, wherein said evaporator unit housing includes second and third compartments each having a different one of said evaporator coil stages therein and each having air passages for communication of air therebetween and from said second compartment into said first compartment, and said housing having air passages for passage of outside air into said third compartment.

(References on following page) References Cited by the Examiner UNITED STATES PATENTS 11/ 1921 Amend 62-255 12/1936 Murphy 62-255 6/ 1941 Booth 62-255 1/ 1950 Spangler 62-255 Geneck 62-255 Pouchert 62-255 Lam-b 62-256 Dickson 62-256 WILLIAM J. WYE, Primary Examiner. 

1. A REFRIGERATED DISPLAY CASE SYSTEM COMPRISING AN EVAPORATOR UNIT INCLUDING A HOUSING HAVING RETURN AIR AND SUPPLY AIR ACCESS OPENINGS THEREIN, EVAPORATOR COIL MEANS IN SAID HOUSING, AND DRIVEN AIR CIRCULATING MEANS IN SAID HOUSING FOR CIRCULATING AIR FROM SAID RETURN OPENING OVER SAID COIL MEANS TO COOL AND DEHUMIDIFY THE AIR AND CONVEY THE SAME TO SAID SUPPLY OPENING; AN OPEN TOP DISPLAY CASE HAVING NO COILS THEREIN FORMING A PHYSICALLY SEPARATE STRUCTURE RELATIVE TO SAID EVAPORATOR HOUSING TO BE COUPLED TO SAID EVAPORATOR UNIT TO RECEIVE AIR FROM AND RETURN AIR TO SAID EVAPORATOR UNIT, SAID DISPLAY CASE HAVING A BOTTOM WALL AND SIDE WALLS AND AN END WALL REMOTE FROM THE EVAPORATOR HOUSING COLLECTIVELY DEFINING AN UPWARDLY OPENING SPACE BETWEEN SAID WALLS, THERMALLY CONDUCTIVE PANEL MEANS WITHIN SAID SPACE DISPOSED IN SUBSTANTIALLY PARALLEL RELATION TO AND SPACED FROM AT LEAST ONE OF SAID WALLS DIVIDING SAID SPACE INTO ELONGATED AIR CIRCULATING DUCT MEANS AND AN UPWARDLY OPENING PRODUCT ZONE DISPOSED ABOVE AT LEAST A PORTION OF SAID DUCT MEANS EACH EXTENDING SUBSTANTIALLY THE ENTIRE LENGTH OF THE DISPLAY CASE, A DIVIDER PARTITION IN SAID DUCT MEANS DIVIDING THE SPACE IN SAID AIR CIRCULATING DUCT MEANS INTO A REFRIGERATED AIR SUPPLY DUCT AND AN AIR RETURN DUCT, SAID AIR SUPPLY DUCT BEING BOUNDED ON ONE SIDE BY AT LEAST A PORTION OF SAID PANEL MEANS ALONG THE LENGTH OF THE DISPLAY CASE TO COOL PRODUCT IN SAID PRODUCT ZONE BY DIRECT THERMAL TRANSFER THEREFROM THROUGH SAID PANEL MEANS PORTION TO DEHUMIDIFIED REFRIGERATED AIR IN SAID AIR SUPPLY DUCT, ORIFICE MEANS AT SELECTED SPACED POINTS ALONG SAID SUPPLY DUCT TO ADMIT AIR THEREFROM INTO SID PRODUCT ZONE, SAID DIVIDER PARTITION HAVING AN OPENING ADJACENT THE REMOTE END WALL OF SAID DISPLAY CASE TO COMMUNICATE AIR FROM SAID SUPPLY DUCT TO SAID RETURN DUCT, AND MEANS COMMUNICATING SAID SUPPLY DUCT AND SAID RETURN DUCT RESPECTIVELY WITH SAID SUPPLY AND RETURN OPENINGS AT THE OPPOSITE END THEREOF RELATIVE TO SAID REMOTE END WALL. 